The goal of this proposed research is to purify catfish (Ictalurus Punctata) pancreatic islet glucagon, somatostatin, pancreatic polypeptide, and other islet polypeptide hormones. The purified hormones will be sequenced. Antibodies will be produced toward the purified islet hormones and used to identify by immuno-cytochemical methods the cells of origin. The antibodies will be used to study biosynthesis of islet polypeptide hormones, in a search for precursor molecules. Cell-free synthesis of islet proteins will be monitored with antibodies to the purified islet polypeptides in an effort to purify the messenger RNA for pancreatic glucagon, somatostatin, and pancreatic polypeptides. The long-range-goal of the project is to obtain messenger RNA preparations enriched for these hormones to serve as templates for synthesis of complementary DNA. The complementary DNA will be used to isolate and study the expression of the genes for these islet polypeptide hormones.